Azo dye and method for its preparation



UNITED STATES PATENT OFFICE AZO DYE AND METHOD FOR ITS PREPARATIONFrancis Hervey Smith, Woodstown, N. J., and\ Crayton Knox Black,Wilmington, Del, assignors to E. I. du Pont de Nemours & Company,Wilmington, Del, a corporation of Delaware No Drawing. ApplicationAugust 4, 1932, Serial No. 627,464

21 Claims. (Cl. 260-40) This invention relates to newv azo dyes and 18parts of 100% hydrochloric acid and 13.8 more particularly refers totetrakisazo dyes esparts of sodium nitrite in the usual way. 11 peciallyadapted for dyeing leather. parts of resorcin were dissolved in 100parts of Formerly, when it was desired to impart cer- Water and 20 partsof sodium hydroxide added.

tain shades to leather, particularly the various The p a ic ac d d a oas dd d maintaining a shades of brown, it was necessary to use a atemperature of Coupling Was p mixture of dyes. This resulted in theproduction After Stirring one 110111 hydrochloric a d a of uneven colorswhich were also quite unstable. addedllntil the solution was i y acid toCongo It is an object of this invention to produce dyes red pepenFreshly e hme r 1mm which may be used for dyeing leather in uniform theSolution was alkahne to YBHQW 1O shades, particularly the various shadesof brown, paper and the dye heated to A Solution without the necessityof using a mixture of dyes. of parts e' Ce(SH) 2 were added and the Astill further object is to produce dyes which pere'ture mamte'med e forFF hoursimpart exceptionally stable colors to leather. A The dye efileered wlthout the add-men of Salt still further object is to producedyes which are and reslurned m 9 935F155 of Water- 18 Parts suitable fordyeing wool and other material. of 109% hydroehlencecld e add-ed and theAdditional objects will appear hereinafter. combinailon tetmmilzed WlthParts These object are attained by the present sodium nitrite at 20 C.for one hour. A solution vention wherein a tetrakisazodye of thefollowof 40 parts of meta'phenylene'dle'mme'sulfomc ing general formulis produced; acid in 400 parts of water were added and then 20 sodiumacetate until the mixture was no longer acid to Congo red paper. The dyewas stirred one hour and filtered cold after salting 10% by v volume. RN*N 1 The dry dye was a black powder which dis- X solved in water togive a yellow-brown solution and in concentrated sulfuric acid to give ared- In this formula R and R." represent aryl groups brown solution. andX represents groups such as halogen, alkyl, It dyed leather a darkred-brown. 3o alkoxy, nitro, carboxyl, sulfonic, hydroxyl, and Itsprobable formula is as follows:

v OH NH:

SOIH N01 N=N N=N M1 CR N3: 35

I N=N N=N l lo: SOIH 40 NH: H H 40 hydrogen. These compounds areproduced by On reducing with sodium hydrosulfite the folcoupling twoequivalents of a diazotized monolowing compounds are obtained: aacyl-diamino or nitro-amino derivative of an ,4,6- aromatic compoundwith a dihydroxy benzene, r r am n -b Sillfonio acid treating theresulting compound to convert the A-d a oes mono-acyl-amino or nitrogroups to .amino 2 groups, then diazotizing and coupling with twoExample equivalents of an aromatic coupling component. 21.8 parts orp-nitroaniline-o-sulfomc acid a The invention will be more completelyunderwere diazotized in the usual manner with 9 parts stood by referenceto the following examples in of hydrochloric acid and Ports of which thequantities are stated i parts b sodium nitrite. 11 parts of resorcindissolved in weight: 100 parts of water were added and sodium ace-Egpwmple 1 tate added until no test was obtained on Congo red paper.When coupling was complete the 55 Parts of piolamio cid were diazotizedw th solution was made alkaline with 20 parts 01 sodium hydroxide andthe diazo body from 19.9 parts of picramic acid was added. When couplingwas complete the dye was reduced, tetrazotized and coupled to M. P. D.sulfonic acid as in Example 1.

The dry dye was a black powder which dissolved in water to give ared-brown solution and in concentrated sulfuric acid to give a bluesolution.

It dyes leather a red-brown.

Its probable formula is as follows:

On reducing with sodium hydrosulfite the following compounds areobtained:

2,4,6-triamino-phenol 2,4-diamino-resorcin SOsH- 2,4,5-triamino-benzenesulfonic acid p-phenylene-diamine-sulfonic acid Example 3 parts ofsulfo-phenyl-methyl-pyrazolone were substituted for the 40 parts ofmeta-phenylene-diamine-sulfonic acid in Example 1.

'The dry dyev was a black powder which dissolved in water to give abrown solution and in concentrated sulfuric acid to give a brownsolution.

It dyed leather a red-brown.

Its probable formula is as follows:

On reducing with sodium hydrosulfite the fol- "Llowing compounds areobtained: I Z I-diamino-resorcin N=N N=N- 1&0: SOzH OH H OH2,4,6-triamino-pheno1 Amino-sulfo-phenyl-methyl-pyrazo1one Example 4parts of R-salt dissolved in excess soda ash solution were substitutedfor the 40 parts of meta-phenylene-diamine-sulfonic acid in Example 1.No sodium acetate was used in the last coupling.

The dry dye was a black powder which dissolved ONE,

in water to give a blue solution and in concentrated acid to give aviolet solution.

It dyed leather a blue-black.

Its probable formula is as follows:

SOnH

SOzH

On reducing with sodium hydrosulfite the following compounds areobtained:

Amino-R-salt 2,4,6-triamino-phenol ZA-diamino-resorcin Example 5 '75parts of H-acid were substituted for the 40 parts ofmeta-phenylene-diamine-sulfonic acid in Example 1.

The dry dye was a black powder which dissolved in water to give a bluesolution and in concentrated sulfuric acid to give a violet solution.

It dyed leather black.

9,027g208- 3 its probable formula is as b it liocloncentratedsulfui'icacidato givea violet solu- OH IIIH:

N=N N=N t It dyedleatherla red-brown. 303E 503E (SH 6H Its probableformula is as follows: On reducing with sodium hydrosulfite thefollowing compounds are obtained: OH so H Amino-H-acid2,4,6-triamino-phenol 2,4-diamino-resorcin R Example 6 sOaH. 5H

15.2 grams of b-resorcylic acid were substituted for the 11 parts ofresorcin in Example 1.

The dry dye was a black powder which dissolved in water to give ayellow-brown solution and in concentrated sulfuric acid to give aredbrown solution.

It dyed leather a red-brown.

Its probable structural formula is as follows:

On reducing with sodium hydrosulfite the following products areobtained:

2,4-diamino-resorcin 1,4-diamino-naphthalene-7-sulfonic acidAmino-resorcin On reducing with sodium hydrosulfite the. followingcompounds are obtained:

. ZAfi-triamino-phenol 2,4,5-triamino-benzene-sulfonic acid2,4-dihydroxy-3,5-diamino-benzoic acid Example? Example 8 19 parts of2,4-dihydroxybenzene sulfonic acid were substituted for the 11 parts ofresorcin in Example 1.

The dry dye was solved. in water tov give a yellow-brown solution and inconcentrated sulfuric acid to give a redbrown solution.

It dyed leather a yellow-brown.

Its probable formulais as follows:

S 0311 NO:

D11 reducing with sodium hydrosulfite the follow-- ing compounds areobtained:

2,4,6-triamino-phenol 2,e,5-triamino-benzene sulfonic acid2,4-dihydroxy-3,5 diamino benzene sulfonic acid diazotized with 18 partsof hydrochloric acid and 13.8 parts of sodium nitrite. 11 parts ofresorcin in parts of water were made strongly alkaline with 20 parts ofsodium hydroxide and the diazo body added. Coupling was rapid. Thesolution wassalted 10% by volume and filtered cold.

The dry dye was a black powder which dissolved in water to give ared-brown solution and I 7 Example 9 14.5., parts of1,3-dihydroxy-4achlorobenzene a black powder which diswere substitutedfor the 11 parts of resorcin in Example 1.

The dry dye was black powder which dissolved in water to give ayellow-brown solution and in concentrated sulfuric acid to give ared-brown solution. It dyed leather a dark-brown.

Its probable formula is as follows:

SOzH No; O] NO;

NH OH On reducing with sodium hydrosulfite the following compounds areobtained:

2,4,6-triamino-phenol 2,4,5-triamino-benzene sulfonic acid2,4-dihydroxy-3,5-diamino-l-chlorobenzene Example 10 125 parts oforcinol were substituted for the parts of resorcin in Example 1. The drydye was a black powder which dissolved in water to give a yellow-brownsolution and in concentrated sulfuric acid to give a redbrown solution.

It dyed leather a dark-brown.

Its probable formula is as follows:

NH OH N=N N=N N=N NH, H 6H 0H On reducing with sodium hydrosulfite thefollowing compounds are obtained:

2,4,6-triamino-phenol 2,4,5-triamino-benzene sulfonic acid2,4-dihydroXy-3,5-diamino-toluene Example 11 11.0 parts of1,2-dihydroxy-benzene were substituted for thel1.0 parts of resorcin inExample 1. V

The dry dye is a black powder which dissolves in water to give ayellow-brown solution and in concentrated sulfuric acid to give ared-brown solution.

On reducing with sodium hydrosulfite the following compounds areobtained:

2,4,6-triamino-phenol 2,4,5-triamino-benzene-sulfonic acid1,2-dihydroxy-4,5-diamino-benzene In carrying out the process of thepresent invention in addition to the compounds used in the aboveexamples for the components represented by R and R", numerous othercompounds may which are the be substituted therefor. For instance,members of the benzene, naphthalene, anthracene, diphenyl,phenyl-naphthyl, dinaphthyl, and carbazole series may be used. Thesemembers may have substituted thereon various groups among following:halogen, alkyl, alkoxy, hydroxy, nitro, amide, carboxyl, sulfonic,aryloxy,

and aralkyl.

In selecting the components represented by R, it is advisable to usenitro-amino or mono-aoyldiamino derivatives of the compounds previouslyreferred to. After diazo-tization and coupling of these components thenitro or mono-acyl-amino group is converted to the amino group bymethods well known to one skilled in the art. For example, to producethe amino group the nitro group may be reduced with calcium sulfhydrateand the mono-acyl-amino group may be treated with sodium hydroxide. Itis, of course, understood that these methods are used merely forpurposes of illustration, since any of the various other well knownmethods may also be used with satisfactory results.

It is also to be understood that the components represented by R may bedissimilar. Likewise, the components represented by B," may bedissimilar. The means for attaining t s result are also well known, oneof them being described for purposes of illustration in Example 2.

In addition to the aromatic compounds previously referred to as suitablefor the components 7 represented by R," other compounds may be used,

such as pyrazolones, aoyl-acetarylides, or other components of thegeneral formula:

SOsH.

Among the components which R" are the following:

may be used for ,B-Naphthol a-NlDhthOl 2-Naphtho1-6-sulfonic acidZ-Naphthol-B-sulfonic acid 2-Naphthol-5-sulfonic acid2Naphthol-.7-sulfonic acid til ' 2-Naphthol-3,7-disulfonic .acid

2-Naphthol-4,8-disulfonic acid 2 Naphthol-BB-disulfonic acidZ-Naphthol-3,6,8-trisulfonic acid l-Naphthol-Z-sulfonit: acid1-Naphthol-4-sulfonic acid 1-Naphthol-5-sulfonic acid 1,6-Cleves acid1,7-Cleves acid Naphthionic acid Phenyl-methyl-pyrazoloneChlor-sulfo-phenyl-methyl-pyrazolone Aceto-acetanilideAceto-acet-ortho-chlor-anilide Methyl indolel-Naphthol-3,6,8-trisulfonic acid a-Naphthylamine 'p-Naphthylamine1-Amino-5-naphthol-7-sulfonic acid l-Amino 'l-naphthol-3-sulfonic acid1-Amino-8-naphthol-4-sulfonic acid 1-Amino-8-naphthol-6-sulfonic acid2-Amino-3-naphthol-6-sulfonic acid 2-Amino- 5-naphthol-7 sulfonic acid2-Amino-7-naphthol-3-sulfonic acid B-Hydroxy-naphthoic acid J-acid ureap-Amino-benzoyl-J-acid Phenyl-J-acid Salicyclic acid Other substituteddihydroxy-benzenes may be used in place of those mentioned in the aboveexamples. Among these substituted dihydroxy benzenes are the following:

Dihydroxy-nitro-benzenes Dihydroxy-anisidines or phenetidinesDihydroXy-brom-benzenes Dihydroxy-fluor-benzenes The products of thepresent invention are.ex-, ceptionally well adapted for dyeing leather,since they produce uniform stable colors, particularly the variousshades of brown, without the necessity of mixing with other dyes'l'hese, colors are greatly superior to those formerly-produced frommixed dyes. In addition, the products may be used for dyeing wool andfor many other purposes. 7

As many apparent andwidely different embodimentsof this invention may bemade without departing from the spirit thereof it is to be understoodthat we do not limit "ourselves to the foregoing examples ordescriptions except as indicated in the following patent claims.

We claim: p i M 1. i A proces s'for producing azo'dyes-which'comprisescoupling two equivalents of a diazotized member selected from the groupconsisting of mono-acyl-diamino and nitro-amino derivatives of anaromatic compound with a dihydroxy-benzene, treating the resultingcompound to convert the mono-acyl-amino or nitro groups to amino groups,then tetrazotizing the product and couplingiit with two .equivalentspfan aromatic coupling component.

2. A process for producing azo dyes which comprises coupling twoequivalents of a diazotized member. selected from thegroup consisting ofmono-acyl-diamino and nitro-amino derivatives of an aromatic compoundwith resorcin, treating the resulting compound to convert themonoacyl-amino or nitro groups to amino groups, then tetrazotizing theproduct and coupling it with two equivalents of an aromatic couplingcomponent.

3. The process of claim 1 wherein the dihydroxy-benzene is coupled withdissimilar components and the resulting product is coupled withcomponents which maybe dissimilar;

4; Aprocess for producing azo dyes which comprises coupling twoequivalents of a diazotized member selectedfrom the group consisting ofmono-acyl-diamino and nitro-amino derivatives of an aromatic compound ofthe benzene series with a dihydroxy-benzene, treating the resultingcompound to convert the mono-acyl-ar nino or nitro groupstoamino-groups, then tetrazotizing the product and coupling it with twoequivalents of an aromatic coupling component.

5. A process for producing azo dyes which comprises coupling twoequivalents of a diazotized member selected from the group consisting ofmono-acyl-diamino and nitro-amino derivatives of an aromatic compoundwith a dihydroxy-ben zene, treating the resulting compound to convertthe mono-acyl-amino or nitro groups to amino groups, then tetrazotizingthe product and coupling it with two equivalents of an aromatic couplingcomponent of the benzene series.

6. A process for producing azo dyes which comprises coupling twoequivalents of a diazotized member selected from the group consisting ofmono-acyl-diamino and nitro-amino derivatives of an aromatic compound ofthe benzene series with a dihydroxy-benzene, treating the recomprisescoupling two equivalents of a diazotized member selected from the groupconsisting of *mono-acyl-diamino and nitro-amino derivatives of anaromatic compound of the benzene series with resorcin, treating theresulting compound to convert the mono-acyl-amino or nitro groups toamino groups, then tetrazotizing the product and coupling it with twoequivalents of an aromatic coupling component of the benzene series.

8. A process for producing azo dyes which comprises coupling twoequivalents of diazotized picramic acid with resorcin, reducing thenitro groups of the resulting compound to amino groups, thentetrazotizing the product and coupling it with two equivalents of anaromatic coupling component of the benzene series which has auxochromegroups substituted thereon.

9. A process for producing an azo dye which comprises coupling twoequivalents of diazotized picramic acid withresorcin, reducing the nitrogroups of the resulting compound to amino groups, then tetrazotizing theproduct and coupling it with two equivalents ofmeta-phenylenediamine-sulfonic acid.

10. A process for producing an azo dye which comprises coupling twoequivalents of diazotized para-nitro aniline-ortho-sulionic acid withresorcin, reducing the nitro groups of the resulting compound to aminogroups, then tetrazotizing theproduct and coupling it with two(equivalents of meta-phenylene-diamine-sulfonic acids. 1

11. A process for producing an azo dye which comprises coupling twoequivalents of diazotized picramic acid with beta resorcylic acid,reducing the nitro groups of the resulting compound to amino groups,then tetrazotizing.theproduct and coupling it with two equivalents ofmeta-phenylene-diamine-sulfonic acid.

as t.

12. Azo dyes having the following general formula: I I

R"-N=NRN=N-XN= r V NRN=NR" wherein R represents the radical of anaromatic coupling component, R represents the radical of an aromaticamine of the benzene series, and X represents the radical of adihydroxy-benzene.

13, Azo dyes having the following general formula:

wherein R" represents the radical of an aromatic coupling component andR represents the rad- -ical of an aromatic amine of the benzene series.

-14. The product of claim 9 wherein the components represented by R aredissimilar and the components represented by R" may be dissimilar.

15. Azo dyes having the following general H formula:

, NR'N=NR" wherein R" represents the radical of an aromatic couplingcomponent of the benzene series, R represents the radical of an aromaticamine of the benzene series, and X represents the radical of adihydroxy-benzene.

SOaH

wherein R" representstheradical of an 'aromatic coupling component ofthe benzene series and R represents the radical of an aromatic amine ofthe benezene series.

17. Azo dyes having the following general formula:

IITO:

H H a V wherein R represents the radical of an aromatic couplingcomponent of the benzene series which has auxochrome groups substitutedthereon.

l8. Tetrakisazo dyes having the following general formula:

wherein R" represents'the radical of a coupling component, R representsthe radical of an aromatic amine of the benzene series, and X representsthe radical of a dihydroxy-benzene, said dye containing at least twosulfonic or'carboxylic acid groups.

19. A tetrakisazo dye having the following formula: i

on n NH,

7, 'OH or '20. A tetrakisazo dye having the following formula: r

SOaH

16. Azo 'dyes having the following general formula:

N=N--R'N=NYR FRANCIS HERVEY SMITH. CRAYTON KNOX BLACK.-

' 55 followlng CERTIFICATE OF CORRECTION.

Patent No. 2,027,206. January 7, 1936.

FRANCIS HERVEY SMITH, ET AL.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 6,first column, line 21 claim 14, for the numeral "9" read 12; and thatthe said Letters Patent should be read with this correction therein thatthe same may conform to the record of the case in the Patent Office.

Signed and sealed this 51st day of March, A. D. 1936.

Leslie Frazer (Seal) Acting Commissioner of Patents.

